I know it is not quite the same thing, but my best friend in life is agnostic. He despises southern Baptists, I hate to say, but I did not know how he felt about Catholics. I went to a party, well really a dinner party, and I told him I had something I wanted to talk to him about.
He thought it was something bad and I just spit it out that I was becoming Catholic. [This was a while ago.] He and I have been friends for decades. He said he was fine with it. “You have always been a seeker.” He said. I don’t have a problem with it if it makes you happy.
Bottom line, if he is a real friend, he will understand and be happy for you.